12 piece set is made in the U.S.A., featuring the SK's High Visibility technology. The sockets are coated with a rust-preventative compound, which makes then exceptionally resistant to corrosive factors. In addition to the rust-preventative coating, the sockets are laser engraved every 120 degrees with extra-large markings for improved readability. All the SK impact sockets feature the SK's SureGrip® hex design, which drives the side of the hex, not the corner. This not only provides increased strength, but also avoids the rounding of rusted or damaged fasteners, which can occur when using a sharp cornered hex tool. Semi-deep impact sockets are designed to provide added reach over standard sockets, yet fit in tight spaces where deep sockets are too long. The nose-down design extends the taper as far as possible, for improved access over straight wall designs. Sizes include: 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm and 19mm sockets.